Shifter-fork plunger



' Patented May 17, 1921.

I d? m I MW M a III) UNYITED'STATES PATENT OFFICE.-

MAXIMILIAN C. FBINS, OF NEW YORK N. Y., ASSIGNOR TO INGWATIONAL MOTORCOMPANY, QF NEW YORK, N. Y., A CORPORATION OF DELAWARE.

SKIPPER-FORK PLUNGER.

Specification of Letters Patent.

Patented May 1'7, 1921.

Applicatlon filed August 26, 19 20. Serial No. 406,157.

To all whom it may concern:

Be it known that I, MAXIMILIAN C. FRINS, a citizen of the United States,residing in the borough of Manhattan of the city of New York, in theState of New York, have plunger. for positioning shifter forks and alsoto an improved association thereof with a positioning1 groove forthe'fork'cut transversely in e sup orting shaft on which the forkslides. eretofor'e, plunge'rs for the purpose noted haveusually beenformed with a generally conical end adapt ed to seat in a similar recessin the shaft or in a transverse groove cut in the shaft. The bearing endfor the plunger hasfheretofore usually afforded acne-point "support withthe result that upon shifting of the fork the nose of the plunger wouldnick the groove at its edge and ultimately ream a longitudinal channelin the shaft along the path of movement of the plunger.-

This nicking has resulted in a breaking down of the holding wall of theoove to such an extent that the fork is o ten accidentally shaken fromits position when the plunger rides loosely out of the nicked groove.Further, the shaft itself is marred and little resistance offered to thefree sliding of the fork. By the improved construction it is soughttoprovide a plunger which is of such character as to prevent thepositioning groove from being nicked or worn to any appreciable extentand to rest on the shaft wit a relatively broad bearing surface so as towear it'uniformly, if at. all, and not mar its exterior surfacel Inaccordance with the invention the nose of-the plunger is formed bytapering it at oppoing surface conforming to the curvature of I theshaft. The entering groove for the side walls and a site sides leaving atransverse blunt nosewhich is milled out concentrically with the shaft'so as to. form a broad and long bearis similarly formed with tapered Inthe preferred form of the invention theplunger is held against rotativemovement within the hub of the fork by means of a positioning. in whichhas a slotted engagement with tiie plunger. 7

7 Reference is now to be had to the accompanying drawing fora detaileddescription of one embodiment of the invention, in

which Figure 1 is a view in elevation'of a shifter fork of approved typeand in section through the hub thereof and the improved positioningplunger, the nose of the plunger being indicated in elevation. i

Fig. 2 is a view in transverse section taken through the hub of theforkshown in Fig. 1 along the plane of the'line 2-2 and looking inthedirection of thearrows,.the shaft and plunger being'shown in plan.

The fork a which-may be of any approved form may be cast as usual withan elongated hub a, through whichpasses a' supporting shaft b alongwhich the fork is slidin amanner' which will be understood. The positionof the fork with its gear is, of

course, determined by the. position in which it is arrestedin itsmovement along the shaft 1). For the purpose of fixing this position andindicating to the operator whena desired position .is reached, it isusual to mount with the hub a a positioning plungervindicated at c andadapted to cooperate with notches or the like, indicated at b.The'plun'geis heretofore employed have "been objectionable in that"their; I I

noses have usually been formed to afford such a hearing; as would nickthe positionindeed, have a tendency. to cut a groove along the shaft inthe path of travel of the plunger with the fork. The present inventionseeks to provide .an improved plunger which is of such form as toeliminate any ing recess or notch in the shaft and would,

reaming action by its-nose on any metal with which it engages.Accordingly, the plunger 0 at its inner end is tapered at Oposite sides,as indicated at c, c terminatmg in a blunt nose,indicated atfc The nose0 is milled out transversely, as indithe supporting shaft 1). Theentering groove cated at 0" along a line substantially concentric. incurvat-urewith the curvature of ally similar form to the end of theplunger verse notches 6', although in some construcc as described inthat this notch has opposed side walls 6 and a broad bottom [2 the formand dimensions being such as toreceive snugly the tapered nose of theplunger. The plunger 0 may be hollow for a portion of its length toreceive a spring 03 which may seat on a plate 6 held against movementsby a cotter pin f which may pass .through the extension a of the hub ain which the plunger is positioned. The cotter pin f rests in opposedslots 0 cut in the side walls of the plunger adjacent its end so as topermit axial movement of the plunger.

In operation it will be evident that the plunger 0 is pressed yieldinglyinto=engagement with the shaft 2) at all times under the influence ofthe spring ol. When the fork a is slid along the shaft by any usualmeans the plunger 0, of course, rides out of the notch b with whichitsnose engages, moving axially against the pressure of the spring (1. Inriding out of the notch b it is evident that one of the tapered sidewalls 0', c

of the nose of the plunger 0 will remain in engagement with one of thetaperedside walls b of the notch until the end of the plunger passes outof the notch when the edge of the curved end 0 of the plunger will havea moment to engage the edge of one of the side walls 6 At that instantthere will be a line of contact of substantial length between the twoedges. This kind of contact will prevent any nicking or undue wear onthe metal of the shaft. When the plunger finally rides on to theexterior surface of theshaft b the curved end 0 will rest snugly i onthe shaft and afford a relatively broad and long bearing surface for theplunger.

The Wear occasioned by the plunger on the shaft will be negligible and,of course, uniform. There will be no tendency for the pluhger to grooveor nick the shaft at any 7 point. The engagement of. the cotter pin withthe slot 0 in the'plunger will maintain it at alltimes in properrelation to the transtions it may be found unnecessaryto provide anysuch positioning devices.

I claim as my invention:

1. Asan article of manufacture, a shifter fork plunger having a noseformed with oppositely tapered side walls terminating in a blunt nosecurved transversely.

2. As an article of manufacture, a shifter fork plunger formed at oneend with oppofork and having oneend formed with oppositely tapered slotsterminatin in a fiatblunt nose curved transversely, said shaft beingprov1ded with cooperating grooves cut transversely to the axis of theshaft and formed 5 similarly to the nose of the plunger.

5. In combination with a shifter fork and a supporting shaft on whichthe fork is slidably mounted, a plunger carried with the fork and havingone endformed with oppositely tapered slots terminating in a flat bluntnose curved transversely along a line concentric to the shaft, saidshaft being pro- .vided with cooperating grooves cut transversely to theaxis of the shaft and formed with opposed side walls tapered similarlyto the tapered nose of the plunger and with a broad flat bottom toreceivethe flat nose of the plunger.

This specification signed this 20th day of August, A. D. 1920.

MAXIMILIAN C. F RINS.

